these days I tend to weigh the project at almost every point, and I have been asked to make a chambered strat body so it seemed like a good idea to keep a track of exactly how much I can control the weight.
I already know that a swiss cheese les paul style gives approx 1oz per hole - which is less than many expect. this is going to be chambered a lot more so lets see how we get on.
The starting point is an african walnut body blank like this - starting at 10.6lb
you can see its only a little oversized for a strat, so potentially quite weighty -
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that's a good thing to know already. Cutting an average sized body blank into an average guitar shape reduces the weight by approx 40%
as it stands the body is still 48mm thick, so to take it to standard strat thickness we need to remove 3.5mm so at proper strat thickness we can estimate this will weight 2.6kg/5.7lb before routing any further
If this was going to be a solid body strat I estimate it would be approx 2kg/4.4lb, maybe it could be shaved down in 4lb with some big contours
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once its chambered the top will likely be bloodwood
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the strong black lines coming from it are typical of african walnut. They look awesome when finished. its not a true walnut, actually its closer to mahogany. But it does work in a similar way to walnut - cuts easily and carving tools leave a really smooth finish
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I agree that the amount that chambers affect weight is surprisingly modest!
I've been recently been building and designing guitars with a scooped back...this does seem to make a bigger difference, but because I've never done the weight checks scientifically, it's more a perception and assumption than a fact. I'm building a humdinger of a scoop-back at the moment and can try to do comparison in a similar fashion. I'll post the results when I've got them if they of any interest.
I suppose the scoop is similar to altering thickness and can be similarly calculated.
Most non trem guitars can easily afford to lose 1/4" from the thickness. At least from a structural and ergonic perspective. Worth remembering that gives an instant 10-15% weight loss for very little effort.
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Taking 7mm off the thickness it is now 2.52kg/5.55lb.
a quick sketch of where the chambered will be
Before I chamber i need to 2 do routes and 2 contours. I did contemplate doing all the routing first, then cutting through the top to reveal once done, but as this will be rear routed I think it will be neater if I do the pickup and neck routes once its altogether.
Also, the strat control layout doesn't really work for a rear routed guitar, the volume is too close to the bridge pickup which is too close to the trem cavity - to I am going to route the strat style control route(slightly enlarged for an additional switch) first deep enough for pots, then do the rear route later. they will cross over a bit on the inside, but look right from the outside. once i thought about that i had to re-position some of the lines i drew on above
i will also route the jack socket although most of the wood behind this will be removed later. once the top is glued on this will leave some support in place for the jack socket
I have also done the forearm and rear contour as i want these in place before i chamber. I did the rear round over too
weighs in at 2.33kg/5.14lb - ready for some hollowing out
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Good stuff man.. Wonder where you got that wood ?
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tbh, I have been looking at Ian's listings for a long time. He always puts the weights on, and it often puts me off as they seem quite heavy... that's kinda the reason for this thread.
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http://www.warmoth.com/Emails/Newsletter/2012-Newsletters/October/newsletter.htm
guitarbuild do similar to warmoth, but with a route only slightly bigger than the f-hole. Both are really "weight relieved" rather than "chambered" or "semi-hollow", if that makes sense.
i will go through the weight relieved stage and take some readings, but then push past it for a large chamber
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even better if you could bring bridge and tuners too so I can ensure best fit of all the parts
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I said i was going to start by weight relieving the guitar before chambering - its easiest if you hog out a lot of wood with a drill first so it makes sense to go through the different weight reduction techniques for this build.
I start with a large forstner drill bit in the drill press. its 1 1/4" wide. I am going 1" deep to start with - that's the safe point with the contour on back, i can always deepen the chamber later if needs be
I proceed to drill 8 more holes which gives us this @2.25/4.9lb - fairly sure one of my previous weights is out as i expected more than 10g per hole - but nor more than 30g per hole. kinda annoying
i started with 9 holes because that is equivilent to traditional gibson weight relief. its not really giveing much weight relief at this stage - a maximum on 0.6lb. on a les paul that might be the difference between a 9 1/2lb and 10lb's - its not the difference between a light and heavy guitar
next step is a lot more holes of the same size
17 holes in total - now down to 2.14kg/4.7lb - okay - that confirms each hole is only giving me 13g weight reduction. We still have not lost a lot of weight. they could safely be 8mm deeper though as i started shallow for the gut cut. it would still not be much more than 1/2lb of weight
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we are now down to 1.95kg/4,3lb - its getting to a nice weight now.
Obviously it looks terrible, and i need to make it a few mm deeper to get rid of the drill points. I don't make a template for the chamber, instead i use a series of straight edges to route 6mm deep along the top edge - this forms my template for going deeper. I probably should just make a template - but this way seems to work
final weigh in at this stage 1.67kg/3.68lb - the final tidy up and deepening of the cavity had a massive effect and we are now into the light weight end of the spectrum. I could still go deeper, but would need to step the cavity to ensure i did not catch the gut cut. I may also extend onto the contour - but want to ensure i have a drop top bent to shape across solid wood before i do
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a nice bit of bookmatched bloodwood - 4mm thick
i need to be quite precise with this so i am going to put a few dowel markers in positions that will be routed away later
I attach it to the body with a few small bits of doublesided tape and drill through
right through to the body
add some dowels
then put the top back in place and trim flush
the dowels then get glued in place so I can accurately position the top without gluing it in place just yet!
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